1. Technical Field
The present invention relates to a seat belt retractor for use in a vehicle. In particular, the present invention relates to a seat belt retractor having a comfort mechanism for relieving the force applied by seat belt webbing against a vehicle occupant.
2. Description of the Prior Art
Seat belt retractors having comfort mechanisms for relieving the force applied by seat belt webbing against a vehicle occupant are known. One such seat belt retractor is disclosed in U.S. Pat. No. 3,682,412 and includes seat belt webbing secured to a spool. The spool is supported for rotation in belt retraction and belt withdrawal directions for winding the seat belt webbing onto or off of the spool. A spring biases the spool to rotate in the belt retraction direction. After the seat belt webbing is buckled around the occupant, the biasing force of the spring pulls the seat belt webbing against the occupant.
To relieve the force of the seat belt webbing acting against the occupant, the retractor includes a comfort mechanism. The comfort mechanism disclosed in U.S. Pat. No. 3,682,412 is manually actuatable. After the seat belt webbing is buckled around the occupant, the occupant withdraws the seat belt webbing a relatively small amount to establish slack in the seat belt webbing. The occupant then manually moves a handle which actuates the comfort mechanism. Rotation of the spool in the belt retraction direction is then blocked and the slack established by the occupant is maintained. During a nonemergency situation, additional seat belt webbing in excess of the slack may be withdrawn from the spool during forward movement of the occupant. When the occupant moves back, the biasing spring rotates the spool in the belt retraction direction. The retractor has a "memory" to re-establish the amount of slack set in the belt webbing by the occupant.